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Abstract:

Electrochemical corrosion potential (ECP) probe assemblies may be used to
monitor ECP of materials due to coolant chemistry in an operating nuclear
reactor. Example embodiment assemblies include at least one ECP probe
that detects ECP of potentially several different materials, a structural
body providing a fluid flow path for the coolant over the ECP probes, and
a signal transmitter that transmits or carries ECP data to an external
receiver. The ECP probes may be of any number and/or type, so as to
detect ECP for different component materials, including stainless steel,
a zirconium alloys, etc. The ECP probes may further detect ECP due to ion
concentration, pH, etc. The ECP data may be transmitted through wired or
wireless signal transmitters. Example methods include installing and
using example embodiment ECP probe assemblies in nuclear reactors and
facilities.

Claims:

1. An electrochemical corrosion potential (ECP) probe assembly useable in
an operating nuclear reactor, the assembly comprising: at least one ECP
probe configured to detect ECP of a component material when a fluid in
the operating nuclear reactor contacts the ECP probe; a structural body
housing the ECP probe and enclosing the fluid so that the fluid flows
through the assembly and contacts the ECP probe; at least one signal
transmission medium configured to transmit the ECP for the component
material from the ECP probe.

2. The assembly of claim 1, wherein the at least one ECP probe is a
plurality of ECP probes, and wherein a first ECP probe of the plurality
of ECP probes and a second ECP probe of the plurality of ECP probes are
configured to detect ECP of different component materials.

3. The assembly of claim 2, wherein the first ECP probe includes
stainless steel and detects ECP of stainless steel, and wherein the
second ECP probe includes a zirconium alloy and detects ECP of the
zirconium alloy.

4. The assembly of claim 2, wherein at least one of the first and the
second ECP probes include platinum and iron ferrite sensors and detect
ECP of the component material due to pH of the fluid.

5. The assembly of claim 1, wherein the structural body includes a single
fluid inlet and a single fluid outlet so as to provide a single fluid
flow path.

6. The assembly of claim 5, wherein the ECP probe is rigidly connected to
the structural body so that the ECP probe is within the single fluid flow
path.

7. The assembly of claim 5, wherein the structural body includes a
venturi at the single fluid inlet and a screen mesh at the single fluid
outlet.

8. The assembly of claim 1, further comprising: a communications port
configured to communicatively connect the signal transmission medium to
an external conduit, wherein the signal transmission medium is a
conductive wire and the ECP of the fluid is transmitted as electrical
signals on the conductive wire.

9. The assembly of claim 1, further comprising: a plurality of extensions
rigidly connected to the structural body, the plurality of extensions
configured to secure the assembly to an external structure; and a
detection window permitting radiation incidence on the ECP probe.

10. A method of installing an electrochemical corrosion potential (ECP)
probe assembly in a nuclear reactor, the method comprising: securing an
ECP probe assembly in a desired orientation and location inside of a
reactor pressure vessel, the ECP probe assembly including, a plurality of
ECP probes each configured to detect ECP of a component material when a
coolant in the nuclear reactor contacts the ECP probe, a structural body
housing the ECP probe and enclosing the coolant so that the coolant flows
through the assembly and contacts the ECP probe, and at least one signal
transmission medium configured to transmit the ECP of the coolant from
the ECP probe; and communicatively connecting the ECP probe to a receiver
outside of the reactor pressure vessel.

11. The method of claim 10, further comprising: determining the desired
location based on components in the reactor pressure vessel in proximity
to the desired location, anticipated coolant conditions at the desired
location, and anticipated radiation levels at the desired location.

12. The method of claim 10, wherein the desired location is on a core
shroud wall at a top of the core in the reactor pressure vessel about a
heat-affected zone of a major weld joint of the core shroud wall.

13. The method of claim 10, wherein the ECP probe assembly further
includes a plurality of extensions rigidly connected to the structural
body, and wherein the securing includes affixing the structural body to a
reactor structure at the desired location via at least one of the
extensions.

14. The method of claim 10, wherein the securing includes positioning the
ECP probe assembly at an orientation with regard to anticipated coolant
flow through the reactor pressure vessel so that the coolant flows
through the ECP probe assembly in a same flow direction as through the
reactor pressure vessel.

15. The method of claim 10, wherein the communicatively connecting
includes connecting a communications conduit between the ECP and an
instrumentation tube in the nuclear reactor, and wherein the
communications conduit contains a transmission medium transmitting ECP
data to the receiver outside the reactor pressure vessel.

16. The method of claim 10, wherein the desired location is on a core
shroud wall at a top of the core in the reactor pressure vessel, and
wherein the communications conduit runs down the core shroud wall to a
core plate and across the core plate to the instrumentation tube.

17. The method of claim 10, wherein a first ECP probe of the plurality of
ECP probes and a second ECP probe of the plurality of ECP probes are
configured to detect ECP for different materials, and wherein the
different materials include stainless steel and a zirconium alloy.

18. A method of installing an electrochemical corrosion potential (ECP)
probe assembly in a nuclear facility, the method comprising: securing an
ECP probe assembly in a desired location in the nuclear facility, the ECP
probe assembly including, an ECP probe configured to detect ECP of a
component material when a fluid in the facility contacts the ECP probe, a
structural body housing the ECP probe and enclosing the fluid so that the
fluid flows through the assembly and contacts the ECP probe, and at least
one signal transmission medium configured to transmit the ECP of the
fluid from the ECP probe; and communicatively connecting the ECP probe to
a receiver in a second location in the nuclear facility.

19. The method of claim 18, wherein the ECP probe is configured to detect
ECP of different materials, wherein the different materials include
austenitic stainless steel and a zirconium alloy.

20. The method of claim 18, wherein the ECP probe assembly further
includes an extension rigidly connected to the structural body, and
wherein the securing includes affixing the structural body to a structure
at the desired location via the extension.

Description:

BACKGROUND

[0001] As shown in FIG. 1, a conventional nuclear reactor, such as a
Boiling Water Reactor (BWR), may include a reactor pressure vessel (RPV)
12 with a generally cylindrical shape. RPV 12 may be closed at a lower
end by a bottom head 28 and at a top end by a removable top head 29. A
cylindrically-shaped core shroud 34 may surround reactor core 36, which
includes several nuclear fuel elements that generate power through
fission. Shroud 34 may be supported at one end by a shroud support 38 and
may include a removable shroud head 39 and separator tube assembly at the
other end. Fuel bundles may be aligned by a core plate 48 located at the
base of core 36. One or more control blades 20 may extend upwards into
core 36, so as to control the fission chain reaction within fuel elements
of core 36. Additionally, one or more instrumentation tubes 50 may extend
into reactor core 36 from outside RPV 12, such as through bottom head 28,
permitting instrumentation, such as neutron monitors and the
thermocouples, to be inserted into and enclosed within the core 36 from
an external position.

[0002] A fluid coolant, such as water, is circulated up through core 36
and core plate 48 and is at least partially converted to steam by the
heat generated by fission in the fuel elements. The steam is separated
and dried in separator tube assembly and steam dryer structures 15 and
exits RPV 12 through a main steam nozzle 3 near top of RPV 12. The
coolant circulated through and boiled in RPV 12 is typically pure and
deionized, except for some additives that enhance coolant chemistry.
While attempts are made to maintain a stable coolant chemistry that is
inert with respect to components and fuel in RPV 12, coolant chemistry
may be adjusted to meet operational needs or changed through component
failure. For example, a soluble neutron absorber may be added to the
coolant to better control the nuclear reaction in core 36, or fission
products may be inadvertently leaked into the coolant through failure of
fuel elements in core 36, or hydrogen may be produced in fuel elements
through high-temperature cladding-coolant reactions.

[0003] Conventionally, coolant chemistry is monitored through several
mechanisms in order to understand coolant chemistry impact on the reactor
internals discussed above and to successfully adjust coolant chemistry to
meet operational needs. For example, electrochemical corrosion potential
(ECP), a property of materials used in the reactor that reflects
corrosion and cracking of the material in various coolant conditions, may
be monitored by ECP probes in contact with circulating coolant. Access to
RPV 12 is limited and difficult during operation and coolant circulation,
such that only specific positions may be available for ECP monitoring.
ECP probes may be placed in various positions in instrumentation tubes 50
and, through sampling holes in instrumentation tubes, contact circulating
coolant to measure component ECP. Other ECP probes may be placed in a
bottom head 28 drain line (not shown) or in other coolant piping to
sample coolant chemistry for component ECP. For example, ECP probes may
be placed in a Mitigation Monitoring System manifold or Recirculation
Piping System and contact coolant flowing therein to measure component
ECP. Similarly, coolant may be extracted from a coolant loop servicing
RPV 12 and raised to reactor-level conditions in a laboratory autoclave,
in order to sample ECP with an ECP probe outside RPV 12.

SUMMARY

[0004] Example embodiments are directed to electrochemical corrosion
potential (ECP) probe assemblies that may be used to monitor component
ECP properties resulting from coolant chemistry in an operating nuclear
reactor. Example embodiment assemblies include at least one ECP probe
that detects component ECP for potentially several different reactor
materials, a structural body providing a fluid flow path for the coolant
over the ECP probes, and a signal transmitter that transmits or carries
ECP data detected by the ECP probes to an external receiver. The ECP
probes may be of any number and/or type, so as to detect ECP for
different component materials, including stainless steel, a zirconium
alloys, etc, exposed to reactor coolant. The ECP probes may further
detect coolant chemistry including ion concentration, pH, etc. that
measures corrosion or cracking potential of materials exposed to the
coolant. The ECP probes may be housed in the structural body in the fluid
flow path such that coolant contact and ECP detection is maximized. The
ECP probe assembly may include a venturi or other structure at the
coolant inlet to enhance fluid flow and ECP detection. The ECP data may
be transmitted through wired or wireless signal transmitters to the
external receiver so that material health within the operating nuclear
reactor may be assessed without accessing the reactor internals.

[0005] Example methods include installing and using example embodiment ECP
probe assemblies in nuclear reactors and facilities. Example methods
include securing the ECP probe assembly in a desired location in the
facility and communicatively connecting the ECP probe to the receiver
that may receive and/or process the ECP data for operating the facility
based on the same. The installation location may be determined based on
components in the facility in proximity to the desired location and/or
anticipated fluid conditions at the desired location. For example, ECP
probe assemblies may be installed on a core shroud wall 34, or at a top
of the core in the reactor pressure vessel 12, where coolant chemistry
has a large impact on reactor operation but has previously been
unobtainable. The ECP probe assembly may include extensions that permit
the assembly to be affixed to a nearby structure at the desired location
through the extensions. Example methods may position the ECP probe
assembly so that the fluid flows through the ECP probe assembly. Example
methods may further connect a communications conduit between the ECP and
an instrumentation tube in a nuclear reactor by running the conduit down
a core shroud wall 34 to a core plate 48 and across the core plate 48 to
the instrumentation tube 50.

BRIEF DESCRIPTION OF DRAWINGS

[0006]FIG. 1 is an illustration of a conventional Reactor Pressure Vessel
and internals.

[0007]FIG. 2 is an illustration of an example embodiment ECP Probe
Assembly.

[0008]FIG. 3 is an illustration of an example embodiment ECP Probe
Assembly installed in a nuclear reactor in example methods.

[0009]FIG. 4 is another illustration of an example embodiment ECP Probe
Assembly installed in a nuclear reactor in example methods.

[0010]FIG. 5 is an illustration of a conduit routing from ECP probes to
instrumentation tubes in a nuclear reactor in example methods.

[0011]FIG. 6 is an illustration of a conduit joining instrumentation
tubes in a nuclear reactor in example methods.

DETAILED DESCRIPTION

[0012] Hereinafter, example embodiments will be described in detail with
reference to the attached drawings. However, specific structural and
functional details disclosed herein are merely representative for
purposes of describing example embodiments. The example embodiments may
be embodied in many alternate forms and should not be construed as
limited to only example embodiments set forth herein.

[0013] It will be understood that, although the terms first, second, etc.
may be used herein to describe various elements, these elements should
not be limited by these terms. These terms are only used to distinguish
one element from another. For example, a first element could be termed a
second element, and, similarly, a second element could be termed a first
element, without departing from the scope of example embodiments. As used
herein, the term "and/or" includes any and all combinations of one or
more of the associated listed items.

[0014] It will be understood that when an element is referred to as being
"connected," "coupled," "mated," "attached," or "fixed" to another
element, it can be directly connected or coupled to the other element or
intervening elements may be present. In contrast, when an element is
referred to as being "directly connected" or "directly coupled" to
another element, there are no intervening elements present. Other words
used to describe the relationship between elements should be interpreted
in a like fashion (e.g., "between" versus "directly between", "adjacent"
versus "directly adjacent", etc.).

[0015] As used herein, the singular forms "a," "an," and "the" are
intended to include the plural forms as well, unless the language
explicitly indicates otherwise. It will be further understood that the
terms "comprises", "comprising," "includes," and/or "including," when
used herein, specify the presence of stated features, integers, steps,
operations, elements, and/or components, but do not preclude the presence
or addition of one or more other features, integers, steps, operations,
elements, components, and/or groups thereof.

[0016] It should also be noted that in some alternative implementations,
the functions/acts noted may occur out of the order noted in the figures
or described in the specification. For example, two figures or steps
shown in succession may in fact be executed in parallel and concurrently
or may sometimes be executed in the reverse order or repetitively,
depending upon the functionality/acts involved.

[0017] The inventors of the present application have identified several
previously-unrecognized problems with conventional electrochemical
corrosion potential (ECP) monitoring devices and methods. For example,
gathering and transmitting ECP data for materials in reactor coolant in
multiple positions within a reactor pressure vessel may not be possible
due to limited access to reactor pressure vessels during operation.
Coolant accessible to ECP probes in instrumentation tubes may have
different chemistry, temperature, pressure, etc., resulting in different
material ECP characteristics, from materials at other important reactor
pressure vessel locations, such as within the reactor core, near shroud
weldings, below a steam dryer, etc. Moreover, radiation levels near these
different locations may vary and have greater impact on material ECP than
near just the instrumentation tubes. As such, it may be difficult to
accurately determine how radiation and coolant affects other reactor
pressure vessel internals that are subject to ECP damage from coolant
chemistry. Further, placement of ECP probes in multiple instrumentation
tubes may limit space available for other types of instrumentation within
the tubes and/or increase the likelihood of coolant leakage into such
tubes. Example embodiments and methods discussed below uniquely address
these previously-unidentified effects of conventional ECP monitoring to
achieve several advantages, including improved material ECP monitoring at
several positions within a nuclear reactor, improved reactor coolant
chemistry control, reduced usage of instrumentation tube space, and/or
other advantages discussed below or not, in nuclear power plants.

Example Embodiments

[0018]FIG. 2 is an illustration of an example embodiment ECP probe
assembly 100. As shown in FIG. 2, ECP probe assembly 100 includes at
least one ECP probe 150. For example, ECP probe assembly may include four
ECP probes 150a, 150b, 150c, 150d, or any other desired number of probes.
ECP probes 150 may be known types of ECP probes. For example, U.S. Pat.
No. 5,192,414, incorporated herein in its entirety by reference,
discloses an ECP probe with a stainless steel electrode for measuring ECP
of stainless steel in coolant. The ECP of, and thus damage potential for,
stainless steel components may be measured by a voltage generated in the
stainless steel electrode when contacted with coolant. Or, for example,
U.S. Pat. Nos. 6,222,307 and 6,623,611, both incorporated herein in their
entirety by reference, disclose other types of ECP probes with platinum
and/or zirconium alloy tips that measure ECP for other materials, such as
zircaloys, based on coolant properties such as pH levels.

[0019] ECP probes 150a, b, c, d may be of a same or different types. For
example, ECP probe 150a and 150d may measure ECP with regard to stainless
steel, while ECP probe 150c may measure ECP with regard to Inconel, while
ECP probe 150b may yet further measure ECP with regard to zircaloy. Any
number and combination of types of ECP probes 150 may be used in example
embodiment ECP probe assembly 100, based on types of materials used in a
subject reactor, based on types of component materials closest to example
embodiments installed in nuclear reactors, and/or based on particular
anticipated types of coolant chemistry, for example. For example, ECP
probes 150c and 150d may be ceramic ball-shaped probes having iron
ferrite sensor particles clustered within the ceramic ball-shaped
structure, and ECP probes 150a and 150b may be platinum-type sensors
having platinum particles in cylindrical probes positioned similarly as
the ceramic ball-shaped probes, 150d and 150c.

[0020] ECP probes 150a, 150b, 150c, and 150d are mounted in example
embodiment ECP probe assembly 100 so as to come into contact with coolant
fluid flow 160 through example embodiment ECP probe assembly 100, such as
during reactor operation. For example, ECP probes 150a, 150b, 150c, and
150d may be mounted in an alignment housing 155 such that active
electrodes at an end of ECP probes 150a, 150b, 150c, and 150d are facing
into coolant fluid flow 160. Alternately, one or more ECP probes 150 may
be at an angle or perpendicular to coolant fluid flow 160. Alignment
housing 155 may rigidly align ECP probes 150 within structural body 110
of example embodiment ECP probe assembly 100. For example, alignment
housing 155 may be welded or otherwise affixed to structural body 110
with, for example, fasteners 101, which may be flat head screws, pins,
tangs, magnets, adhesives, etc.

[0021] Structural body 110 may be generally enclosed to contain and force
coolant fluid flow 160 through example embodiment ECP probe assembly 100
so as to maintain ECP probe 150 contact with active coolant for ECP
monitoring. An exit filter 190, such as a screen mesh or perforated
plate, may permit fluid coolant flow 160 to exit structural body 110 and
capture any parts of ECP probe assembly 100 that may potentially detach
into the coolant. A detection window 151 (FIG. 4) may be included in
structural body 110 over ECP probes 150a, 150b, 150c, 150d, etc.
Detection window 151 may be transparent to light or certain types of
radiation, such that probes may detect radiation within the reactor,
including alpha, beta, and electromagnetic radiation such as Cherenkov
radiation. For example, detection window 151 may be an uncovered opening
to permit maximum exposure.

[0022] Alternately, structural body 110 may include or form other holes or
openings to adjust coolant flow, pressure, etc. as desired within
structural body 110. Structural body 110 is shown with a generally
rectangular cross-section and may, for example, have rectangular
cross-section dimensions of about 4 inches by 3 inches. Of course,
structural body 100 may have any shape or size that accommodates at least
one ECP probe 150 and coolant flow 160, including cylindrical, square,
conical, etc. Structural body shape and size may be varied to achieve a
desired liquid coolant flow 160 rate or mass flow, to achieve a desired
positioning within a subject reactor, and/or to achieve any other desired
operational characteristic.

[0023] Example embodiment ECP probe assembly 100 further includes an inlet
for fluid coolant flow 160 to flow within structural body 110 and exit
190. The inlet may include a venturi 120 that increases a speed of liquid
coolant flow 160 through the example embodiment assembly 100 and/or
collects liquid coolant flow 160 from a larger flow cross section in a
reactor, to better estimate average coolant chemistry. Alternatively,
other inlet structures, including diffusers, choke plates, filters, etc.
may be used instead of, or in combination with, venturi 120 in example
embodiment ECP probe assemblies to generate desired coolant flow and
content. Venturi 120 or any other structure may be affixed to structural
body 110 with fasteners 101 or any other joining mechanism, including
welding or friction, for example.

[0024] As fluid coolant flows through example embodiment ECP probe
assembly 100, one or more ECP probes 150 generate an electrical or other
signal indicative of the ECP of a relevant material in the coolant flow.
These signals may be transmitted through transmission media 141, which
may include wires or other circuitry, for example. Transmission media 141
may also include wireless transmitters that transmit signals from ECP
probes 150 through electromagnetic waves, for example, to an external
receiver. Although ECP probes 150 may operate without external power,
electrical or otherwise, transmission media 141 may supply power to any
components of example embodiment ECP probe assembly 100. Transmission
media may be communicatively connected to ECP probes 150 and exit
assembly 100 through a communications port 140.

[0025] An access plate 130 may be removable from structural body 110 to
provide specific access to a component inside example embodiment ECP
probe assembly 100, particularly if the assembly 100 is installed in an
area preventing removal or other access. Example embodiment ECP probe
assembly 100 may further include one or more external securing structures
such as mid-body extension(s) 170 and/or foot extension(s) 175. Extension
170 and/or 175 may permit joining, fastening, tying, etc. example
embodiment ECP probe assembly 100 to an external component so as to
rigidly secure assembly 100 in a particular vertical position within a
reactor. For example, mid-body extensions 170 may accommodate a bolt
therethrough to join assembly 100 to a flange. In this way, example
embodiment ECP probe assembly 100 may be secured in a desired location to
measure coolant ECP properties near a particular reactor component
without repositioning or loss of coolant flow 160 during reactor
operation. Of course, other joining/fixing devices and mechanisms are
useable with example embodiment assemblies to ensure a desired positional
characteristic.

[0026] The components described above, useable with example embodiment ECP
probe assemblies, may be manufactured from materials designed to
withstand operating conditions within a nuclear reactor. For example, any
of venturi 120, structural body 110, alignment housing 155, and/or
extension 175 and 170 may be fabricated from zircaloys, austenitic
stainless steel, nickel alloys, etc. that substantially maintain their
physical properties in high pressure/temperature aqueous environments
with elevated levels and types of radioactivity. Or, for example,
materials used in example embodiment ECP probe assemblies may be chosen
to match materials to which the probe will be installed, so as to
minimize material incompatibility and fouling.

[0027] Example embodiment ECP probe assemblies are thus useable in several
harsh environments such as operating nuclear power reactors. It is
understood that several features discussed above in connection with
example embodiments may be reconfigured or omitted based on the specific
application and/or desired operational characteristics of an ECP probe
assembly. While example embodiment ECP probe assembly 100 may be
installed and used in accordance with example methods discussed below, it
is understood that other uses and installation locations may be
applicable with example embodiment probe assemblies.

Example Methods

[0028] Example methods include installing an ECP probe assembly, such as
example embodiment ECP probe assembly 100, in a nuclear reactor. Example
methods include determining a location for installation of the ECP probe
assembly within a nuclear power plant. Any location may be chosen that is
in contact with coolant flowing in the operating reactor. The location
does not depend on instrumentation tube access or other reactor vessel
aperture access. For example, as shown in FIG. 3, a position about an
inner circumferential surface of a core shroud 34, at a flange just below
shroud head 39, may be a position of interest due to its proximity to
welds within core shroud 34, elevated radiation levels experienced by
these components and welds, and/or coolant chemistry at the position due
to coolant possessing a high thermal energy after exiting core 36 (FIG.
1), just below the position. Because no or few vessel apertures or other
access points may be near the position on core shroud 34, example
embodiment ECP probe assemblies installed there may permit unique data
gathering for improved plant operation and monitoring. As such a
position, ECP probe assemblies may detect metal chemistry near a
heat-affected zone of a major weld joint on the core shroud wall 34, and
ECP probes 150a, 150b, 150c, and 150d may be aligned vertically within
about 0.25 inch away from the detected metal surface so as to achieve
accurate ECP measurement. Other positions within the nuclear plant and/or
nuclear reactor may be chosen based on similar interests in material ECP
properties in the coolant.

[0029] The ECP probe assembly may be installed in the desired position so
as to receive and monitor material ECP properties at the position. The
installation may occur during plant fabrication, during a fuel outage, or
during any other periods when the location is accessible. The ECP probe
assembly may be installed through several known methods of securely
positioning components within a nuclear reactor. For example, ECP probe
assembly 100 may be welded to a surface of core shroud 34 in FIG. 3. Or,
as shown in FIG. 4, for example, foot extensions 175 (FIG. 2) may be
bolted with lug bolts and/or pins 170 to a flange of core shroud 34 just
below shroud head 39. Several alternate methods of installing and
securing an ECP probe assembly at the desired position are possible,
including use of fasteners, screws, tang/receptor matings, or mechanisms
involving tying, friction, or adhesives.

[0030] Once installed at the desired position, power operations or other
events within the nuclear reactor may be commenced that cause coolant
flow 160 through ECP probe assembly 100. Although not necessary, ECP
probe 100 may be installed with regard to known coolant flow 160 to
permit fluid coolant to flow through ECP probe assembly 100 as it flows
through the reactor vessel. For example, a clearance may be maintained
about a coolant exit from ECP probe assembly 100 so as to ensure coolant
flow 160 through the assembly. Coolant coming into contact with
individual ECP probes within the ECP probe assembly 100 during operations
may be monitored for material ECP properties. For example, ECP probes
measuring ECP of stainless steel and zircaloys may come into contact with
active coolant and detect stainless steel or zircaloy ECP from the
coolant at the location of the ECP probe assembly 100. Through the ECP
probe detection, material corrosion and potential cracking due to coolant
effects near the location of ECP probe 100 for actual reactor materials
may be accurately estimated.

[0031] ECP probes may transmit the data, including voltages reflecting
corrosion, pH, other free ions, etc., directly to a user through
transmitters in installed ECP probe assemblies, using electromagnetic
signals detected by a user receiver outside the reactor, for example. If
ECP probe assemblies installed in example methods require a hard-wired
connection to transmit signals, a transmission conduit may further be
installed in example methods. For example, as shown in FIG. 4, a
transmission conduit 200 may be installed from a communications port 140,
as shown in FIG. 2, in example embodiment ECP probe assembly 100 down the
wall of core shroud 34 onto core plate 48. The transmission conduit 200
may be, for example, a radiation-hardened 1-inch or smaller pipe or
tubing that insulates and separates transmission media 141, which may be
a mineral-insulated wire within the tubing, carrying ECP data from ECP
probes.

[0032] Transmission conduit 200 as shown in FIG. 4 may bend, change
direction, or join to other features in order to provide a route for
communications from ECP probe assembly 100. One or more braces 210 may
secure and/or guide transmission conduit 200 against a core shroud 34
wall or other component, so as to prevent transmission conduit 200
loosening or vibration, for example.

[0033] As shown in FIG. 5, the transmission conduit 200 extend down a wall
of core shroud 34 to core plate 48, where it bends or is otherwise routed
onto core plate 48 to instrumentation tube 50 passing through core plate
48. In this routing, the transmission conduit 200 may have a minimal
impact on coolant flow through a nuclear reactor and/or may not otherwise
interfere with reactor operation. Transmission media 141 (FIG. 2) may run
entirely through transmission conduit 200 without exposure to reactor
coolant. Radiation and/or thermal shielding may be provided in
transmission conduit 200 to minimize reactor operating conditions on
transmission media 141. For example, as discussed above transmission
media 141 may be a mineral insulated wire.

[0034] As shown in FIG. 6, where transmission conduit 200 joins to
instrumentation tube 50, transmission media 141 may pass from
transmission conduit 200 into instrumentation tube 50. The joining may be
sealed, by welding 250 for example, to prevent coolant entry into
instrumentation tube 50. Transmission media 141 may then be fed down
instrumentation tube 50 outside of the reactor, communicatively
connecting to conventional data acquisition system processing devices
located in the drywell exterior to the reactor pressure vessel 12.
Alternatively, transmission conduit 200 may join to any other aperture,
used for instrumentation or otherwise, in a reactor vessel so as to feed
data externally.

[0035] Upon installation of ECP probe assembly 100 and configuring and
receiving data from the ECP probe assembly of material ECP at the
installed position during reactor operation, plant operators may
accurately assess coolant chemistry effects on plant components. Because
example methods permit example embodiment ECP probe assemblies to be
installed in several positions inaccessible during plant operation, and
because example embodiment ECP probe assemblies may be configured with
desired ECP probe types, ECP of a variety of different materials at
several different positions with respect to several different components
may be remotely assessed within an operating nuclear reactor. Plant
operators may adjust plant chemistry components based on the data
received from installed ECP probe assemblies during plant operation so as
to improve component health, reduce component damage, etc.

[0036] Example embodiments and methods thus being described, it will be
appreciated by one skilled in the art that example embodiments may be
varied through routine experimentation and without further inventive
activity. Variations are not to be regarded as departure from the spirit
and scope of the example embodiments, and all such modifications as would
be obvious to one skilled in the art are intended to be included within
the scope of the following claims.